This disclosure relates to novel aqueous ink-jet inks containing an aqueous vehicle, a cross-linked pigment dispersion, and a cross-linked polyurethane binder. The inks improves image properties when printed, and are particularly advantageous for printing on textile.
Ink-jet digital printing method is becoming increasingly important for the printing of textiles. It offers a number of potential benefits over conventional printing methods such as screen printing. Digital printing eliminates the set-up expense associated with screen preparation and can potentially enable cost-effective short run production. Digital printing furthermore allows visual effects, such as tonal gradients and repeat of printed patterns that cannot be practically achieved with a screen printing process. Especially beneficial is the ease in changing the patterns of originals during production of digital printing, when it is possible to respond to a change in patterns or other requirements within a short period of time.
U.S. Patent Application Publication No. 20050182154 discloses an inkjet ink containing cross-linked polyurethanes as a binder for printing on textile.
U.S. Patent Application Publication No. 20130137816 discloses an inkjet ink containing a self-dispersing pigment or pigment dispersed by a polyurethane dispersant followed by cross-linking the polyurethane dispersant.
WO03/029318 describes polyurethane block copolymers as dispersants for inks. These polyurethanes are cross-linked prior to inversion (addition of water to produce the polyurethane dispersion) not during or after inversion. There is also crosslinking derived from the added melamine crosslinker which is only effective at high temperatures and/or acidic conditions that occur at the time of the textile treatments after printing.
A need exists for stable ink-jet inks with superior jetting properties that can be printed on various substrates to form durable, high quality image. The present disclosure satisfies this need by providing an ink containing a colorant that is dispersed by a polyurethane dispersant followed by crosslinking, and a cross-linked polyurethane binder which is different from the polyurethane dispersant.